Synonym/Acronym
CBC.
Rationale
To evaluate numerous conditions involving red blood cells (RBCs), white blood cells (WBCs), and platelets. This test is also used to indicate inflammation, infection, and response to chemotherapy.
Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.
Normal Findings
(Method: Automated, computerized, multichannel analyzers; using either traditional electrical impedance or flow cytometry for cell counts and myeloperoxidase staining for WBC differential. Many of these analyzers are capable of determining a five- or six-part WBC differential.) This battery of tests includes hemoglobin, hematocrit, RBC count, RBC morphology, RBC indices, RBC distribution width index (RDWCV and RDWSD), platelet count, platelet size, immature platelet fraction (IPF), WBC count, and WBC differential. The six-part automated WBC differential identifies and enumerates neutrophils, lymphocytes, monocytes, eosinophils, basophils, and immature granulocytes (IG), where IG represents the combined enumeration of promyelocytes, metamyelocytes, and myelocytes as both an absolute number and a percentage. The five-part WBC differential includes all but the IG parameters.
Hemoglobin
| Age | Conventional Units | SI Units (Conventional Units × 10) |
|---|
| Cord blood | 13.5–19.5 g/dL | 135–195 g/L | | 0–1 wk | 14.5–22.5 g/dL | 145–225 g/L | | 2–3 wk | 13.3–20.5 g/dL | 133–205 g/L | | 1–2 mo | 10.7–18 g/dL | 107–180 g/L | | 3–6 mo | 9–13.5 g/dL | 90–135 g/L | | 7 mo–15 yr | 10.3–13.3 g/dL | 103–133 g/L | | 16–18 yr | 11–15 g/dL | 110–150 g/L | | Adult | | | | Male | 14–17.3 g/dL | 140–173 g/L | | Female | 11.7–15.5 g/dL | 117–155 g/L | | Pregnant Female | | | | First trimester | 11.6–13.9 g/dL | 116–139 g/L | | Second and third trimesters | 9.5–11 g/dL | 95–110 g/L |
Values are slightly lower in older adults. Reference range values may vary among laboratories. Note: See “Hemoglobin and Hematocrit” study for more detailed information. |
Hematocrit
| Age | Conventional Units (%) | SI Units (Conventional Units × 0.01) (Volume Fraction) |
|---|
| Cord blood | 41–59 | 0.41–0.59 | | 0–1 wk | 44–68 | 0.44–0.68 | | 2–3 wk | 40–62 | 0.4–0.62 | | 1–2 mo | 31–55 | 0.31–0.55 | | 3–6 mo | 27–41 | 0.27–0.41 | | 7 mo–15 yr | 31–43 | 0.31–0.43 | | 16–18 yr | 33–45 | 0.33–0.45 | | Adult | | | | Male | 42–52 | 0.42–0.52 | | Female | 36–48 | 0.36–0.48 | | Pregnant Female | | | | First trimester | 35–42 | 0.35–0.42 | | Second and third trimesters | 28–33 | 0.28–0.33 |
Values are slightly lower in older adults. Reference range values may vary among laboratories. Note: See “Hemoglobin and Hematocrit” study for more detailed information. |
WBC Count and Differential
| Age | Conventional Units WBC × 103/microL | Neutrophils | Lymphocytes | Monocytes | Eosinophils | Basophils |
|---|
| | (Absolute) and % | (Absolute) and % | (Absolute) and % | (Absolute) and % | (Absolute) and % | | Birth | 9.1–30.1 | (5.5–18.3) 24%–58% | (2.8–9.3) 26%–56% | (0.5–1.7) 7%–13% | (0.02–0.7) 0%–8% | (0.1–0.2) 0%–2.5% | | 1–23 mo | 6.1–17.5 | (1.9–5.4) 21%–67% | (3.7–10.7) 20%–64% | (0.3–0.8) 4%–11% | (0.2–0.5) 0%–3.3% | (0–0.1) 0%–1% | | 2–10 yr | 4.5–13.5 | (2.4–7.3) 30%–77% | (1.7–5.1) 14%–50% | (0.2–0.6) 4%–9% | (0.1–0.3) 0%–5.8% | (0–0.1) 0%–1% | | 11 yr–older adult | 4.5–11.1 | (2.7–6.5) 40%–75% | (1.5–3.7) 12%–44% | (0.2–0.4) 4%–9% | (0.05–0.5) 0%–5.5% | (0–0.1) 0%–1% |
Notes: SI Units (Conventional Units × 1 or WBC × 109/L). See “WBC Count, Blood Smear and Differential” study for more detailed information. |
WBC Count and Differential
| Age | Immature Granulocytes (Absolute) (103/microL) | Immature Granulocyte Fraction (IGF) (%) |
|---|
| Birth–9 yr | 0–0.03 | 0%–0.4% | | 10 yr–older adult | 0–0.09 | 0%–0.9% |
|
RBC Count
| Age | Conventional Units (106 cells/microL) | SI Units (1012 cells/L) (Conventional Units × 1) |
|---|
| Cord blood | 4.41–6.21 | 4.41–6.21 | | 0–1 wk | 4.71–7.31 | 4.71–7.31 | | 2–3 wk | 4.31–6.51 | 4.31–6.51 | | 1–2 mo | 3.41–5.81 | 3.41–5.81 | | 3–6 mo | 3.11–4.51 | 3.11–4.51 | | 7 mo–15 yr | 3.71–5.21 | 3.71–5.21 | | 16–18 yr | 4.01–5.41 | 4.01–5.41 | | Adult | | | | Male | 4.51–6.01 | 4.51–6.01 | | Female | 4.01–5.51 | 4.01–5.51 |
Note: See “RBC Count, Indices, Morphology, and Inclusions” study for more detailed information. |
RBC Indices
| Age | MCV (fl) | MCH (pg/cell) | MCHC (g/dL) | RDWCV | RDWSD |
|---|
| Cord blood | 107–119 | 35–39 | 31–35 | 14.9–18.7 | 51–66 | | 0–1 wk | 104–116 | 29–45 | 24–36 | 14.9–18.7 | 51–66 | | 2–3 wk | 95–117 | 26–38 | 26–34 | 14.9–18.7 | 51–66 | | 1–2 mo | 81–125 | 25–37 | 26–34 | 14.9–18.7 | 44–55 | | 3–11 mo | 78–110 | 22–34 | 26–34 | 14.9–18.7 | 35–46 | | 1–15 yr | 74–94 | 24–32 | 30–34 | 11.6–14.8 | 35–42 | | 16 yr–adult | | | | | | | Male | 77–97 | 26–34 | 32–36 | 11.6–14.8 | 38–48 | | Female | 78–98 | 26–34 | 32–36 | 11.6–14.8 | 38–48 | | Older adult | | | | | | | Male | 79–103 | 27–35 | 32–36 | 11.6–14.8 | 38–48 | | Female | 78–102 | 27–35 | 32–36 | 11.6–14.8 | 38–48 |
MCH = mean corpuscular hemoglobin; MCHC = mean corpuscular hemoglobin concentration; MCV = mean corpuscular volume; RDWCV = coefficient of variation in RBC distribution width index; RDWSD = standard deviation in RBC distribution width index Note: See “RBC Count, Indices, Morphology, and Inclusions” study for more detailed information. |
RBC Morphology
| Morphology | Within Normal Limits | 1+ | 2+ | 3+ | 4+ |
|---|
| Size | | | | | | | Anisocytosis | 0–5 | 5–10 | 10–20 | 20–50 | Greater than 50 | | Macrocytes | 0–5 | 5–10 | 10–20 | 20–50 | Greater than 50 | | Microcytes | 0–5 | 5–10 | 10–20 | 20–50 | Greater than 50 | | Shape | | | | | | | Poikilocytes | 0–2 | 3–10 | 10–20 | 20–50 | Greater than 50 | | Burr cells | 0–2 | 3–10 | 10–20 | 20–50 | Greater than 50 | | Acanthocytes | Less than 1 | 2–5 | 5–10 | 10–20 | Greater than 20 | | Schistocytes | Less than 1 | 2–5 | 5–10 | 10–20 | Greater than 20 | | Dacryocytes (teardrop cells) | 0–2 | 2–5 | 5–10 | 10–20 | Greater than 20 | | Codocytes (target cells) | 0–2 | 2–10 | 10–20 | 20–50 | Greater than 50 | | Spherocytes | 0–2 | 2–10 | 10–20 | 20–50 | Greater than 50 | | Ovalocytes | 0–2 | 2–10 | 10–20 | 20–50 | Greater than 50 | | Stomatocytes | 0–2 | 2–10 | 10–20 | 20–50 | Greater than 50 | | Drepanocytes (sickle cells) | Absent | Reported as present or absent | | | | | Helmet cells | Absent | Reported as present or absent | | | | | Agglutination | Absent | Reported as present or absent | | | | | Rouleaux | Absent | Reported as present or absent | | | | | Hemoglobin Content | | | | | | | Hypochromia | 0–2 | 3–10 | 10–50 | 50–75 | Greater than 75 | | Polychromasia | | | | | | | Adult | Less than 1 | 2–5 | 5–10 | 10–20 | Greater than 20 | | Newborn | 1–6 | 7–15 | 15–20 | 20–50 | Greater than 50 |
Note: See “RBC Count, Indices, Morphology, and Inclusions” study for more detailed information. |
RBC Inclusions
| Inclusions | Within Normal Limits | 1+ | 2+ | 3+ | 4+ |
|---|
| Cabot rings | Absent | Reported as present or absent | | | | | Basophilic stippling | 0–1 | 1–5 | 5–10 | 10–20 | Greater than 20 | | Howell-Jolly bodies | Absent | 1–2 | 3–5 | 5–10 | Greater than 10 | | Heinz bodies | Absent | Reported as present or absent | | | | | Hemoglobin C crystals | Absent | Reported as present or absent | | | | | Pappenheimer bodies | Absent | Reported as present or absent | | | | | Intracellular parasites (e.g., Plasmodium, Babesia, trypanosomes) | Absent | Reported as present or absent | | | |
Note: See “RBC Count, Indices, Morphology, and Inclusions” study for more detailed information. |
Platelet Count, MPV, IPF
| Age | Platelet Count Conventional Units | Platelet Count SI Units (Conventional Units × 1) | MPV (fl) | IPF (%) |
|---|
| Birth | 150–300 × 103/microL | 150–300 × 109/L | 8.1–12.2 | 1.6–7.1 | | 6–23 mo | 200–450 × 103/microL | 200–450 × 103/microL | 8.1–12.2 | 1.7–4.8 | | 2–5 yr | 150–400 × 103/microL | 150–400 × 103/microL | 8.1–12.2 | 1.3–3.9 | | 6–17 yr | 150–450 × 103/microL | 150–450 × 103/microL | 8.1–12.2 | 1.3–6.7 | | Adult, older adult | 150–450 × 103/microL | 150–450 × 109/L | 8.1–12.2 | 1.1–11.1 |
Platelet counts may decrease slightly with age. Note: For additional information, refer to the study titled “Platelet Count and Tests of Platelet Function.” |
Hemoglobin
Adults and Children
- Less than 6.6 g/dL (SI: Less than 66 mmol/L)
- Greater than 20 g/dL (SI: Greater than 200 mmol/L)
Newborns
- Less than 9.5 g/dL (SI: Less than 95 mmol/L)
- Greater than 22.3 g/dL (SI: Greater than 223 mmol/L)
Hematocrit
Adults and Children
- Less than 19.8% (SI: Less than 0.2 volume fraction)
- Greater than 60% (SI: Greater than 0.6 volume fraction)
Newborns
- Less than 28.5% (SI: Less than 0.28 volume fraction)
- Greater than 66.9% (SI: Greater than 0.67 volume fraction)
WBC Count (on Admission)
- Less than 2 × 103/microL (SI: Less than 2 × 109/L)
- Absolute neutrophil count of less than 0.5 × 103/microL (SI: Less than 0.5 × 109/L)
- Greater than 30 × 103/microL (SI: Greater than 30 × 109/L)
Platelet Count
Timely notification to the requesting health-care provider (HCP) of any critical findings and related symptoms is a role expectation of the professional nurse. A listing of these findings varies among facilities.
The presence of abnormal cells, other morphological characteristics, or cellular inclusions may signify a potentially life-threatening or serious health condition and should be investigated. Examples are the presence of sickle cells, moderate numbers of spherocytes, marked schistocytosis, oval macrocytes, basophilic stippling, eosinophil count greater than 10%, monocytosis greater than 15%, nucleated RBCs (if patient is not an infant), malarial organisms, hypersegmented neutrophils, agranular neutrophils, blasts or other immature cells, Auer rods, Döhle bodies, marked toxic granulation, or plasma cells.
Study type: Blood collected in a lavender-top [EDTA] tube or Microtainer; related body system: Circulatory/Hematopoietic and Immune systems. Blood from a green-top (lithium or sodium heparin) tube may be submitted, but the following automated values may not be reported: WBC count, WBC differential, platelet count, IPF, and mean platelet volume. The specimen should be analyzed within 24 hr when stored at room temperature or within 48 hr if stored at refrigerated temperature. If it is anticipated the specimen will not be analyzed within 24 hr, two blood smears should be made immediately after the venipuncture and submitted with the blood sample. Smears made from specimens older than 24 hr may contain an unacceptable number of misleading artifactual abnormalities of the RBCs, such as echinocytes and spherocytes, as well as necrobiotic WBCs.
A complete blood count (CBC) is a group of tests used for basic screening purposes. It is probably the most widely ordered laboratory test. Results provide the enumeration of the cellular elements of the blood, measurement of RBC indices, and determination of cell morphology by automation and evaluation of stained smears. The results can provide valuable diagnostic information regarding the overall health of the patient and the patient’s response to disease and treatment. Detailed information is found in studies titled “Hemoglobin and Hematocrit,” “RBC Count, Indices, Morphology, and Inclusions,” “Platelet Count and Tests of Platelet Function,” and “WBC Count, Blood Smear and Differential.”
Factors That May Alter the Results of the Study
- Failure to fill the tube sufficiently (less than three-fourths full) may yield inadequate sample volume for automated analyzers and may be a reason for specimen rejection.
- Hemolyzed or clotted specimens should be rejected for analysis.
- Elevated serum glucose or sodium levels may produce elevated mean corpuscular volume values because of swelling of erythrocytes.
- Recent transfusion history should be considered when evaluating the CBC.
Before the Study: Planning and Implementation
Teaching the Patient What to Expect
- Discuss how this test can assist in evaluating general health and monitoring the body’s response to illness and treatment.
- Explain that a blood sample is needed for the test.
Safety Considerations
Make sure a written and informed consent has been signed prior to administering any blood or blood products.
After the Study: Implementation & Evaluation Potential Nursing Actions
Treatment Considerations
- The results of a CBC should be carefully evaluated during transfusion or acute blood loss because the body is not in a state of homeostasis and values may be misleading.
- Considerations for draw times after transfusion include the type of product, the amount of product transfused, and the patient’s clinical situation.
- Generally, specimens collected an hour after transfusion will provide an acceptable reflection of the effects of the transfused product.
- Measurements taken during a massive transfusion are an exception, providing essential guidance for therapeutic decisions during critical care.
Nutritional Considerations
- Instruct patient to consume a variety of foods within the basic food groups, maintain a healthy weight, be physically active, limit salt intake, limit alcohol intake, and avoid use of tobacco.
Clinical Judgement
- Consider how to address cultural and religious fears associated with blood transfusion.
Follow-Up and Desired Outcomes
- Acknowledges the importance of adhering to the recommended diet and medications.